One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,6)(3,5,7,8)(9,10,13,16)(11,14,18,22)(12,15,20,24)(17,21,19,23)(25,26,32,40,31,37,30,36)(27,28,29,33,38,39,34,35)(1,3,4,7)(2,5,6,8)(9,11)(10,14)(12,19)(13,18)(15,23)(16,22)(17,20)(21,24)(25,27,31,38)(26,33,37,35)(28,36,39,40)(29,32,34,30)(2,6)(5,8)(9,12)(10,15)(11,17)(13,20)(14,21)(16,24)(18,19)(22,23)(25,28,31,39)(26,34,37,29)(27,36,38,40)(30,35,32,33)(12,20)(15,24)(17,19)(21,23)(25,29,30,27,31,34,32,38)(26,35,36,39,37,33,40,28)(10,16)(11,18)(15,24)(17,19)(25,30,31,32)(26,36,37,40)(27,29,38,34)(28,33,39,35)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.